Impulsive force simulation of the rubber ball sieve-cleaning device for batch seed cleaners

Abstract: A batch seed cleaner is a piece of special equipment to meet the specific processing of plot breeding materials. A rubber ball sieve-cleaning device can usually be used as an accessory for a seed cleaner to keep sieve cleaning and avoid sieve-mesh blocking. The sieve-cleaning performance of rubber ball sieve-cleaning devices has an important influence on the operation efficiency and quality of batch seed cleaners. The impulsive force of the rubber ball on the sieve is the key factor to determining the cleaning performance. In this study, the structural and working principles of rubber ball sieve-cleaning devices were introduced to theoretically analyze the random elastic collision screening of rubber balls for the accurate acquisition of impulsive force. An EDEM-MBD coupling model was built for a batch seed cleaner using Hertz-Mindlin in contact mode. A piece of sieve-developed test equipment was utilized to measure the contact parameters, such as the restitution coefficient and friction coefficient for the contact model. A rubber ball impulsive force measurement device was built to obtain the real force of a single ball, according to strain-force measurement. The average and the maximum impulsive force of a single rubber ball were effectively obtained, with the acceptable relative errors between the simulation and measured value, less than 5 % and 10%, respectively. The Box-Behnken experiments with four-factor and three-level were conducted to simulate the impulsive force of sieve-cleaning devices under different working conditions. The mathematical relationships were established between the average or the maximum impulsive force and parameters, such as the amplitude, vibration frequency, screening inclination angle, and ball number. The impulsive force of the rubber ball sieve-cleaning device under different parameters was easily obtained using regression equations. The maize seeds cleaning test under different vibration frequencies was carried out with the index of blockage number, where the relationship was between the blockage number of sieve and impulsive force of the sieve-cleaning device. The test results show that the sieve-cleaning device presented an excellent performance with no blockage on the sieve, with an average impulsive force of 8.87 N and the maximum impulsive force of 18.78 N, when the vibration frequency was 7.2 Hz. An optimal combination was achieved for the screening performance if the average impulsive force not less than 9 N or the maximum impulsive force not less than 19 N. The finding can provide a strong design reference for the screening mechanism and parameter optimization of rubber ball sieve-cleaning devices.